IPAC2014 - List of Authors (Melnychuk, O.S.)

Paper	Title	Page
WEPRI053	Phase Method of Measuring Cavity Quality Factor	2604
	O.S. Melnychuk, R.V. Pilipenko, Y.M. Pischalnikov, W. Schappert, D.A. Sergatskov Fermilab, Batavia, Illinois, USA
	Novel method for measuring intrinsic quality factor of superconducting RF (SRF) cavities using both amplitude and phase information of forward, reflected, and transmitted cavity signal is discussed. Advantages of the method in comparison with traditional types of cavity quality factor measurements are highlighted. Computer simulations and evaluation of uncertainties for the measurements are described. Analysis of data collected at vertical test facility for SRF cavities at Fermilab is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI053
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WEPRI054	Medium Field Q-Slope Studies in Low Beta Resonators	2608
	O.S. Melnychuk, A. Grassellino, A.I. Sukhanov Fermilab, Batavia, Illinois, USA
	Studies of the phenomenon of Medium field Q-slope (MFQS, 30-80 mT) have been focused predominantly on high beta superconducting cavities. Complementing research on cavity losses with the analysis of low beta cavity data can provide additional insights into the nature of MFQS. We present MFQS measurements of 325MHz β=0.2 single spoke resonators and 650MHz β=0.9 elliptical single cell resonators at vertical test facility at FNAL. We compare our findings with those obtained for high frequency 1.3GHz cavities tested both at the same facility and other laboratories.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI054
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WEPRI062	The Joint High Q0 R&D Program for LCLS-II	2627
	M. Liepe, R.G. Eichhorn, F. Furuta, G.M. Ge, D. Gonnella, G.H. Hoffstaetter Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA A.C. Crawford, A. Grassellino, A. Hocker, O.S. Melnychuk, A. Romanenko, A.M. Rowe, D.A. Sergatskov Fermilab, Batavia, Illinois, USA R.L. Geng, A.D. Palczewski, C.E. Reece JLab, Newport News, Virginia, USA M.C. Ross SLAC, Menlo Park, California, USA
	The superconducting RF linac for LCLS-II calls for 1.3 GHz 9-cell cavities with an average intrinsic quality factor Q0 of 2.7·10¹⁰ at 2K and 16 MV/m accelerating gradient. A collaborative effort between Cornell University, FNAL, and JLab has been set up with the goal of developing and demonstrating a cavity treatment protocol for the LCLS-II cavities meeting these specifications. The high Q0 treatment protocol is based on nitrogen doping of the RF surface layer during a high temperature heat treatment. This novel SRF cavity preparation was recently developed at FNAL and shown to result in SRF cavities of very high Q0 at 2K with an increase in Q0 from low to medium fields. N-doped single cell cavities at Cornell, FNAL, and JLab routinely exceed LCLS-II specification. 9-cell N-doped cavities at FNAL achieve an average Q0(T=2K, 16 MV/m) of ≈ 3.4·10¹⁰ with an average quench field of ≈ 19 MV/m, meeting therefore overall with good margin the LCLS-II specification.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI062
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Phase Method of Measuring Cavity Quality Factor

2604

O.S. Melnychuk, R.V. Pilipenko, Y.M. Pischalnikov, W. Schappert, D.A. Sergatskov
Fermilab, Batavia, Illinois, USA

Novel method for measuring intrinsic quality factor of superconducting RF (SRF) cavities using both amplitude and phase information of forward, reflected, and transmitted cavity signal is discussed. Advantages of the method in comparison with traditional types of cavity quality factor measurements are highlighted. Computer simulations and evaluation of uncertainties for the measurements are described. Analysis of data collected at vertical test facility for SRF cavities at Fermilab is presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI053

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRI054

Medium Field Q-Slope Studies in Low Beta Resonators

2608

O.S. Melnychuk, A. Grassellino, A.I. Sukhanov
Fermilab, Batavia, Illinois, USA

Studies of the phenomenon of Medium field Q-slope (MFQS, 30-80 mT) have been focused predominantly on high beta superconducting cavities. Complementing research on cavity losses with the analysis of low beta cavity data can provide additional insights into the nature of MFQS. We present MFQS measurements of 325MHz β=0.2 single spoke resonators and 650MHz β=0.9 elliptical single cell resonators at vertical test facility at FNAL. We compare our findings with those obtained for high frequency 1.3GHz cavities tested both at the same facility and other laboratories.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI054

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRI062

The Joint High Q0 R&D Program for LCLS-II

2627

M. Liepe, R.G. Eichhorn, F. Furuta, G.M. Ge, D. Gonnella, G.H. Hoffstaetter
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
A.C. Crawford, A. Grassellino, A. Hocker, O.S. Melnychuk, A. Romanenko, A.M. Rowe, D.A. Sergatskov
Fermilab, Batavia, Illinois, USA
R.L. Geng, A.D. Palczewski, C.E. Reece
JLab, Newport News, Virginia, USA
M.C. Ross
SLAC, Menlo Park, California, USA

The superconducting RF linac for LCLS-II calls for 1.3 GHz 9-cell cavities with an average intrinsic quality factor Q0 of 2.7·10¹⁰ at 2K and 16 MV/m accelerating gradient. A collaborative effort between Cornell University, FNAL, and JLab has been set up with the goal of developing and demonstrating a cavity treatment protocol for the LCLS-II cavities meeting these specifications. The high Q0 treatment protocol is based on nitrogen doping of the RF surface layer during a high temperature heat treatment. This novel SRF cavity preparation was recently developed at FNAL and shown to result in SRF cavities of very high Q0 at 2K with an increase in Q0 from low to medium fields. N-doped single cell cavities at Cornell, FNAL, and JLab routinely exceed LCLS-II specification. 9-cell N-doped cavities at FNAL achieve an average Q0(T=2K, 16 MV/m) of ≈ 3.4·10¹⁰ with an average quench field of ≈ 19 MV/m, meeting therefore overall with good margin the LCLS-II specification.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI062

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)